Mounting means for abrasive products



June 21, 1966 l. J. HOLDASH 3,256,645

MOUNTING MEANS FOR ABRASIVE PRODUCTS Filed 001?. 23, 1963 Rzg. E

lllllll lllllllllllllll lllll INVENTOR I2 VIN J HOL DASH United States Patent 3 256,645 MOUNTING MEANS l OR ABRASIVE PRODUCTS Irvin J. Holdash, Shrewsbury, Mass, assignor to Norton Cltlmpany, Worcester, Mass, a corporation of Massac usetts Filed Oct. 23, 1963, Ser. No. 318,328 2 Claims. (Cl. 51-206) This invention relates to abrasive or like products and more especially to improved means for securely holding the faces of the abrasive wheel or segments of a wheel between the flanges of the clamping means which support and help drive the wheel or segments for rotation about its center.

Customarily, this is provided for by inserting relatively thin discs of blotter-like paper between each clamping element and the face of the abrasive product. The blotter discs are supplied to the purchaser of the wheel; assembled between the clamps and wheel faces, when the wheel is made ready for mounting on the driving spindle; and are colored, printed, and/or marked to identify the product and the manufacturer. More sophisticated means for improving the grip of the clamps on the wheel faces are illustrated in the Gammeter patents, 1,709,820, dated April 16, 1-929, and 1,738,472, dated December 3, 192:9, wherein a liquid rubber derivative is sprayed on each surface of the wheel so as to fill the interstices and rigid metal plates, coated on one side with a thin layer of rubber, are vulcanized to the coated areas of the wheel.

The principal objects of this invention are to provide means permanently attached to the faces of the wheel which will be sufficiently soft and thick to compensate for irregularities and coarseness in the faces of the wheel so as to transmit the clamping forces thereto uniformly; which will be sufiiciently tough to resist the shearing forces developed during grinding operations; which will provide a sufficient coefficient of friction between the clamping elements and the faces to resist slippage; which is of negligible weight, inexpensive to apply and will receive identifying markings; which will not become detached, dislodged or lost; which can be custom made and printed for any type product on the assembly line therebyeliminating large inventories of many different sizes, shapes, etc. of previously printed blotters kept on hand to meet sudden demands; and which will not decompose or swell under operating conditions.

As herein illustrated, the invention comprises applying a layer of particulate yieldable material to each face of the wheel, which is substantially coextensive with the surface portions of the faces with which the clamping means are to have contact, of a thickness to compensate for the irregularities in the faces of the wheel and thereby to distribute the clamping pressure to the wheel uniformly throughout said areas. The layer is comprised of nonadhesive particles resistant to shear and having a relative high coeificient of friction and is distributed uniformly but discontinuously with the particles optionally in parallel or random posture. The particles are of a fibrous character of artificial or natural origin having a particle size in the order of 0.017 inch in length and .005 inch in diameter and are preferably distributed in a layer of approximately 0.017 inch thick and at a density of up to 50,000 per square inch, and upon which markings can be clearly printed or stencilled.

The invention will now be described in greater detail with reference to the accompanying drawings wherein:

FIG. 1 is a diametrical section through an abrasive wheel embodying the invention, shown mounted on a driving spindle;

FIG. 2 is an elevation of the wheel illustrating a printed yieldable layer applied in random posture to one face of the wheel and in the area normally contacted by the flange of the clamping means at that side and showing a fragmentary portion of the clamping means; and

FIG. 3 is a detail illustrating an enlarged section of the Wheel and the cushion layer laid in parallel posture.

One of many possible applications of the invention is shown and described as applied to a typical grinding wheel. As herein illustrated (FIG. 1), abrasive wheel 10 is mounted in conventional fashion on a drive spindle 14 betwen clamping plates 16 which have annular peripheral flanges 18, adapted to have contact with the side faces of the wheel radially outward from the center and to be clamped to the side faces between a bushing 20 at one side mounted on the spindle against a shoulder 22 one the spindle and a nut 24 threaded onto the spindle at the other side. If desired, the flanges 16 may be keyed to the spindle 14 to provide a more positive drive.

In accordance with the purpose of this invention, to improve the frictional contact and hence the drive between the clamping elements 16 and the wheel, the portion of each face of the wheel, throughout an area which is substantially coextensive with the clamps, is coated with a layer 26 of yieldable particulate material of suflicient thickness to compensate for irregularities in the faces of the wheel and thereby to distribute the clamping pressure, applied by the clamping elements, to the wheel uniformly throughout the area of their contact. In some instances it may be desirable to coat the whole area extending from the hole to beyond the peripheral edge of the flanges covering an area compatible to that covered by the conventional paper blotters. This method would be preferred if the flanegs 18 are made to contact a larger portion of the area about the hole in the wheel in order to increase the frictional driving surface, or if additional room is required for printing markings or legends thereon. The layer 26 is comprised of a plurality of small discrete particles attached by an adhesive layer 30 to the face of the wheel. The particulate layer has a thickness in the order of 0.017 inch-it being understood, however, that the thickness of the layer will depend entirely upon the coarseness of the face of the wheel, since the purpose of the layer is to compensate for the irregularities produced by this coarseness and hence to eliminate high points which would produce points of excessive stress in the wheel by reason of the clamping action of the clamps, and to increase the area of frictional contact between the clamping means and the faces of the wheel.

Preferably the particulate material is of a fibrous character comprised of natural or artificial fibers, such as cotton, wool, wood, rayon, and the like, having a lengthwise dimension of about 0.017 inch and a diameter of about .005 inch. A distribution of about 50,000 fiber particles per square inch has proved very effective.

The particles are applied to the surfaces of the wheel by supporting the wheel, together with masks covering the areas, which are not to be coated, on a conveyor in vertical position, spraying adhesive on the areas of the wheel which are not covered by the mask and then spraying the particulate material on the adhesive coated areas. Spray guns may be employed both for the purpose of applying the adhesive and the particulate material. Application of the fibers in this fashion is extremely uniform and produces a wholly satisfactory blotter-like surface on the faces of the wheel: The particulate material and the guns for applying the adhesive and the particles are commercially available and may be obtained from Cellusuede Products, Inc, of Rockford, Illinois.

Application of the particles by means of spray .gun equipment is uniform, however, the disposition of the particles is random. If a uniform posture of particles is desired, the wheels may be subjected to vibration in horizontal planes during and/or following application of the fibers so as to dispose a major portion of the fibers parallel to the surfaces to which they are applied. If it is preferred that the particles stand up on end substantially at right angles to the surfaces, the particles may be applied to the surfaces while the wheels are being moved through an electrostatic field. Apparatus for applying the particles, ether to cause them to be disposed parallel to the surface of the wheels or perpendicular thereto, are available from the foregoing Cellusuede Products, Inc., and by slight modification may be adapted for the purpose of applying blotter layers to the faces of grinding wheels for the purpose described herein.

In whatever fashion the layer is applied after it has set, it provides a surface which may be marked by printing and/or stenciling to identify the manufacturer or distributor of the wheel, together with any other information or legends which may be desired.

If desired, the mask may be cut in a well known manner so that the legends, instead of being printed thereon,

may be produced by spraying the particulate material through the mask in different colors if necessary having the desired legends therein. In this way the legends and frictional particulate material can be applied in one operation. The fiber selection will naturally be designed to affor the properties required for the size and character of the wheel and should afford sufficient resistance to shear and a sufficient coefficient of friction to prevent slipping of the wheel between the clamping means under the maximum torque expected to be encountered under ope'ratand supported between rotating clamping means, said area having a substantially uniformly distributed layer of individual fibers thereon, said fiibers being selected from a group consisting of cotton, wool, wood, rayon and mixtures thereof, said fibers having the characteristics of being non-adhesive, yieldable, and high co-efficient of friction material, each fiber of said layer having a long and a short axis, each of said fibers being adhesively secured only at one end ofthe longer of said axes to said face substantially throughout said area, the secured fibers being arranged in closely juxtaposed position for mutual support, said layer being resistant to sheer when said clamping means rotate, and said layer having a thickness equal to the length along the longer axis of said fibers to compensate for irregularities in the faces of the abrasive product and the flanges whereby to distribute the clamping pressure to the product uniformly throughout said engaged area, and the exposed surface of said layer having a density to accept intelligible legends imprinted thereon.

2. An abrasive wheel adapted to be rotatably driven having parallel side faces adapted to have an area thereof engaged and supported between rotating clamping means for rotation of the wheel about a center; a substantially uniformly distributed layer of individual fibers thereon, said fibers being selected from a group consisting of cotton, wool, wood, rayon and mixtures thereof, said fibers having the characteristics of being non-adhesive, yieldable, and high co-efficient of friction material,

each fibre being in the order of .005 of an inch in diameter and .017 of an inch in length, each of said fibers in the layer being adhesively secured only at one of its longer ends to one of said faces in said area, the secured fibers being arranged in closely juxtaposed position for mutual support, said layer being resistant to sheer when said clamping means rotate, and said layer having a density of approximately 50,000 fibers per square inch to accept intelligible legends imprinted thereon.

References Cited by the Examiner UNITED STATES PATENTS 1,386,743 9/1921 Trudel 5l168 1,600,064 9/1926 Perks 51--206 1,944,489 1/1934 Bockshe 5l168 1,998,919 4/1935 Ballet al. 51-168 2,259,554 10/1941 Clark 51168 2,388,697 11/1945 Lombard 5l168 2,760,313 8/1956 Harvey -51 209' ROBERT C. 'RIORDON, Primary Examiner.

LESTER M. SWINGLE, Examiner.

J. A. MATHEWS, Assistant Examiner. 

1. AN ABRASIVE PRODUCT ADAPTED TO BE ROTATABLY DRIVEN HAVING FACES ADAPTED TO HAVE AN AREA THEREOF ENGAGED AND SUPPORTED BETWEEN ROTATING CLAMPING MEANS, SAID AREA HAVING A SUBSTANTIALLY UNIFORMLY DISTRIBUTED LAYER OF INDIVIDUAL FIBERS THEREON, SAID FIBERS BEING SELECTED FROM A GROUP CONSISTING OF COTTON, WOOL, WOOD, RAYON AND MIXTURES THEREOF, SAID FIBERS HAVING THE CHARACTERISTICS OF BEING NON-ADHESIVE, YIELDABLE, AND HIGH CO-EFFICIENT OF FRICTION MATERIAL, EACH FIBER OF SAID LAYER HAVING A LONG AND A SHORT AXIS, EACH OF SAID FIBERS BEING ADHESIVELY SECURED ONLY AT ONE END OF THE LONGER OF SAID AXES TO SAID FACE SUBSTANTIALLY THROUGHOUT SAID AREA, THE SECURED FIBERS BEING ARRANGED IN CLOSELY JUXTAPOSED POSITION FOR MUTUAL SUPPORT, SAID LAYER BEING RESISTANT TO SHEER WHEN SAID CLAMPING MEANS ROTATE, AND SAID LAYER HAVING A THICKNESS EQUAL TO THE LENGTH ALONG THE LONGER AXIS OF SAID FIBERS TO COMPENSATE FOR IRREGULARITIED IN THE FACES OF THE ABRASIVE PRODUCT AND THE FLANGES WHEREBY TO DISTRIBUTE THE CLAMPING PRESSURE TO THE PRODUCT UNIFORMLY THROUGHOUT SAID ENGAGED AREA, AND THE EXPOSED SURFACE OF SAID LAYER HAVING A DENSITY TO ACCEPT INTELLIGIBLE LEGENDS IMPRINTED THEREON. 